scholarly journals Outage Probability and Ergodic Capacity of a Two-User NOMA Relaying System with an Energy Harvesting Full-Duplex Relay and Its Interference at the Near User

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6472
Author(s):  
Hoang Van Toan ◽  
Tran Manh Hoang ◽  
Tran Trung Duy ◽  
Le The Dung
Keyword(s):  
Energy Harvesting ◽  
Fading Channels ◽  
Power Distribution ◽  
Interference Cancellation ◽  
Ergodic Capacity ◽  
Base Station ◽  
Full Duplex ◽  
Distribution Factor ◽  
Relay System ◽  
Outage Probabilities

In this paper, we consider a two-user downlink full-duplex (FD) non-orthogonal multiple access (NOMA) relay system where the FD relay uses an energy harvesting (EH) technique to assist the communication between the base station and far user over flat, independent and non-identically Rayleigh fading channels. Importantly, since the relay operates in FD mode, we take into account the effect of the interference caused by relay on the near user. Considering this EH-FD-NOMA relay system, we derive the exact mathematical expressions of the outage probabilities and ergodic capacities of near and far users. Monte–Carlo simulations verify the accuracy of our analytical method. Numerical results provided in this paper allow system designers to clearly see not only the impacts of the power distribution factor and the self-interference cancellation capacity of the relay but also the influence of the strength of inter-user interference at the near user on the outage performances and ergodic capacities of both users.

scholarly journals Multi-Points Cooperative Relay in NOMA System with N-1 DF Relaying Nodes in HD/FD Mode for N User Equipments with Energy Harvesting

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 167 ◽  
Author(s):  
Thanh-Nam Tran ◽  
Miroslav Voznak
Keyword(s):  
Energy Harvesting ◽  
Fading Channels ◽  
Interference Cancellation ◽  
Relay Node ◽  
Base Station ◽  
Cooperative Relay ◽  
Proposed Model ◽  
Excess Power ◽  
Multi Access ◽  
Near Future

Non-Orthogonal Multiple Access (NOMA) is the key technology promised to be applied in next-generation networks in the near future. In this study, we propose a multi-points cooperative relay (MPCR) NOMA model instead of just using a relay as in previous studies. Based on the channel state information (CSI), the base station (BS) selects a closest user equipment (UE) and sends a superposed signal to this UE as a first relay node. We have assumed that there are N UEs in the network and the N-th UE, which is farthest from BS, has the poorest quality signal transmitted from the BS compared the other UEs. The N-th UE received a forwarded signal from N - 1 relaying nodes that are the UEs with better signal quality. At the i-th relaying node, it detects its own symbol by using successive interference cancellation (SIC) and will forward the superimposed signal to the next closest user, namely the ( i + 1 ) -th UE, and include an excess power which will use for energy harvesting (EH) intention at the next UE. By these, the farthest UE in network can be significantly improved. In addition, closed-form expressions of outage probability for users over both the Rayleigh and Nakagami-m fading channels are also presented. Analysis and simulation results performed by Matlab software, which are presented accurately and clearly, show that the effectiveness of our proposed model and this model will be consistent with the multi-access wireless network in the future.

scholarly journals On Outage Probability and Ergodic Rate of Downlink Multi-User Relay Systems with Combination of NOMA, SWIPT, and Beamforming

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4737 ◽  
Author(s):  
Ta Chi Hieu ◽  
Nguyen Le Cuong ◽  
Tran Manh Hoang ◽  
Do Thanh Quan ◽  
Pham Thanh Hiep
Keyword(s):  
Energy Harvesting ◽  
Outage Probability ◽  
Fading Channels ◽  
System Performance ◽  
Interference Cancellation ◽  
Base Station ◽  
Optimal Time ◽  
Relay Nodes ◽  
Channel State ◽  
Relay Systems

A downlink of multi-user non-orthogonal multiple access (NOMA) relay systems is considered. To improve system performance, relay nodes are used to forward signals from the base station (BS) to the end users, and they are wirelessly powered by energy harvesting from the radio frequency transmitted from the BS. Moreover, beamforming is applied at the BS based on multiple antennas and relay nodes consist of one transmit antenna but several receive ones. The system performance is demonstrated through closed-form expressions of outage probability (OP) and ergodic rate (ER) over Rayleigh fading channels. The proposed system is investigated in two cases of perfect and imperfect successive interference cancellation (SIC), and the imperfect channel state information condition is also taken into consideration. The OP and ER are calculated in many scenarios and the optimal time fraction of energy harvesting corresponding to the minimum OP is discussed. The exact and approximate theoretical results are compared with the simulation result to confirm the proposed theoretical analysis method.

scholarly journals Multi-Points Cooperative Relay in NOMA System with N-1 DF Relaying Nodes in HD/FD mode for N User Equipments with Energy Harvesting

2018 ◽  
Author(s):  
Thanh-Nam Tran ◽  
Miroslav Voznak
Keyword(s):  
Energy Harvesting ◽  
Fading Channels ◽  
Interference Cancellation ◽  
Relay Node ◽  
Base Station ◽  
Cooperative Relaying ◽  
Proposed Model ◽  
Excess Power ◽  
Multi Access ◽  
Near Future

Non-Orthogonal Multiple Access (NOMA) is the key technology promised to be applied in next-generation networks in the near future. In this study, we propose a multi-points cooperative relaying (MPCR) NOMA model instead of just using a relay as the previous studies. Based on the channel state information (CSI), the base station (BS) selects a closest user equipment (UE) and sends a superposed signal to this UE as a first relay node. We have assumed that there are N UEs in the network and Nth UE, which is farthest from BS, has the poorest quality signal transmitted from the BS compared other UEs. Nth UE received the forwarded signal from N-1 relaying nodes that are UEs with better signal quality. At the ith relaying node, it detect its own symbol by using successive interference cancellation (SIC) and will forward the composite signal to the next closest user, namely i+1th UE, and include an excess power which will use for energy harvesting (EH) intention at the next UE. By these, the farthest UE in network can be significantly improved. In addition, closed-form expressions of outage probability for users over both the Rayleigh and Nakagami-m fading channels are also presented. Analysis and simulation results performed by Matlab software which are presented accurately and clearly show that the effectiveness of our proposed model and this model consistents with the multi-access wireless network in future.

scholarly journals On the Capacity of Full-Duplex AF/DF Relay System with Energy Harvesting for Vehicle-to-Vehicle Communications

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ba Cao Nguyen ◽  
Xuan Hung Le ◽  
Van Duan Nguyen ◽  
Le The Dung
Keyword(s):  
Energy Harvesting ◽  
Rayleigh Fading ◽  
Base Station ◽  
Full Duplex ◽  
High Signal ◽  
Transmission Power ◽  
Time Duration ◽  
Relay System ◽  
Vehicle To Vehicle ◽  
The Impact

This paper studies the ergodic capacity (EC) of full-duplex (FD) amplify-and-forward (AF) and decode-and-forward (DF) relay system with energy harvesting (EH) for vehicle-to-vehicle (V2V) communications. Unlike previous works on FD-EH systems, we consider the case that both relay and destination are mobile vehicles while the source is a static base station. We mathematically derive the exact closed-form expressions of ECs of both AF and DF protocols of the considered FD-EH-V2V relay system over cascade (double) Rayleigh fading. Our numerical results show that the ECs in the case of the V2V communication system are reduced compared to those in the case of stationary nodes. Also, with a specific value of residual self-interference (RSI), the ECs of the considered FD-EH-V2V relay system can be higher or lower than those of half-duplex- (HD-) EH-V2V system, depending on the average transmission power of the source. Furthermore, when the transmission power of the source and RSI are fixed, the ECs of the considered system can achieve peak values by using optimal EH time duration. On the other hand, the ECs of both AF and DF protocols reach the capacity floors in the high signal-to-noise ratio (SNR) regime due to the RSI impact. Also, the effect of RSI dominates the impact of cascade Rayleigh fading in the high SNR regime. Finally, we validate our analysis approach through Monte-Carlo simulations.

On the Study of Cognitive Bidirectional Relaying with Asymmetric Traffic Demands

Frequenz ◽  
2015 ◽  
Vol 69 (5-6) ◽  
Author(s):  
Xiaodong Ji
Keyword(s):  
Ergodic Capacity ◽  
Base Station ◽  
Transmission Protocol ◽  
Splitting Algorithm ◽  
Performance Simulation ◽  
Information Theoretic ◽  
Primary Users ◽  
Operating Region ◽  
Bidirectional Relaying ◽  
Outage Probabilities

AbstractIn this paper, we consider a cognitive radio network scenario, where two primary users want to exchange information with each other and meanwhile, one secondary node wishes to send messages to a cognitive base station. To meet the target quality of service (QoS) of the primary users and raise the communication opportunity of the secondary nodes, a cognitive bidirectional relaying (BDR) scheme is examined. First, system outage probabilities of conventional direct transmission and BDR schemes are presented. Next, a new system parameter called operating region is defined and calculated, which indicates in which position a secondary node can be a cognitive relay to assist the primary users. Then, a cognitive BDR scheme is proposed, giving a transmission protocol along with a time-slot splitting algorithm between the primary and secondary transmissions. Information-theoretic metric of ergodic capacity is studied for the cognitive BDR scheme to evaluate its performance. Simulation results show that with the proposed scheme, the target QoS of the primary users can be guaranteed, while increasing the communication opportunity for the secondary nodes.

scholarly journals Performance Analysis for Exact and Upper Bound Capacity in DF Energy Harvesting Full-Duplex with Hybrid TPSR Protocol

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Phu Tran Tin ◽  
Phan Van-Duc ◽  
Tan N. Nguyen ◽  
Le Anh Vu
Keyword(s):  
Energy Harvesting ◽  
Upper Bound ◽  
Relay Node ◽  
Ergodic Capacity ◽  
Cooperative Relaying ◽  
Spectrum Efficiency ◽  
Full Duplex ◽  
Power Splitting ◽  
Decode And Forward ◽  
Relaying System

In this paper, we investigate the full-duplex (FD) decode-and-forward (DF) cooperative relaying system, whereas the relay node can harvest energy from radiofrequency (RF) signals of the source and then utilize the harvested energy to transfer the information to the destination. Specifically, a hybrid time-power switching-based relaying method is adopted, which leverages the benefits of time-switching relaying (TSR) and power-splitting relaying (PSR) protocols. While energy harvesting (EH) helps to reduce the limited energy at the relay, full-duplex is one of the most important techniques to enhance the spectrum efficiency by its capacity of transmitting and receiving signals simultaneously. Based on the proposed system model, the performance of the proposed relaying system in terms of the ergodic capacity (EC) is analyzed. Specifically, we derive the exact closed form for upper bound EC by applying some special function mathematics. Then, the Monte Carlo simulations are performed to validate the mathematical analysis and numerical results.

scholarly journals Performance Analysis of Full-Duplex Amplify-and-Forward Relay System with Hardware Impairments and Imperfect Self-Interference Cancellation

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Ba Cao Nguyen ◽  
Xuan Nam Tran
Keyword(s):  
Interference Cancellation ◽  
Signal To Noise Ratio ◽  
Relay Node ◽  
Analytical Framework ◽  
Full Duplex ◽  
High Signal ◽  
Amplify And Forward ◽  
Relay System ◽  
Hardware Impairments ◽  
The Impact

In this paper, we analyze the performance of a full-duplex (FD) amplify-and-forward (AF) relay system with imperfect hardware. Besides the aggregate hardware impairments of the imperfect transceiver, we also consider the impact of residual self-interference (RSI) due to imperfect cancellation at the FD relay node. An analytical framework for analyzing the system performance including exact outage probability (OP), asymptotic OP, and approximate symbol error probability (SEP) is developed. In order to tackle these impacts, we propose an optimal power allocation scheme which can improve the outage performance of the FD relay node, especially at the high signal-to-noise ratio (SNR) regime. Numerical results are presented for various evaluation scenarios and verified using the Monte Carlo simulations.

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